Brendan created the character of Agnes for radio and stage shows, before adapting them for the BBC in 2011

“I don’t feel pressure to top the ratings,” insists the Irishman. “What I do feel is pressure to come up with an episode that’s good enough for Christmas Day.”

“Dad loves working under pressure,” chips in Brendan’s son Danny, who plays Buster in the show. “That’s when he comes out with his best stuff. I always wonder how he manages to think up new ideas, but he always seems to pull it out of the bag.”

“It’s hard to say where the ideas come from,” adds Brendan.

“I get them mostly from listening to people – even what sounds like a mundane story can completely change once you add Agnes Brown into the mix. Sometimes I’ll be writing a script and it can come to me all in a day or two, but I swear there are others that take a month!”

Does anyone else in the family help with writing the scripts?

“He will not let anybody touch his baby,” grins Danny, 33. “He won’t bring writers in to help and he’s the same with us when we give suggestions; he won’t take them on board and he doesn’t really ask our advice.

“But he has earnt that right. It was a bit of a shocker when we were given the script for this year’s Christmas episode because there is always a mad Christmas tree involved, but there isn’t this time because Mammy decides she doesn’t want one.

“When the time comes to do rehearsals, sometimes one of us will suggest something to put in and Dad will either tell us to f*** off or say it’s a great idea.

“I always tell him if I think a joke doesn’t work and he’ll say: ‘Danny, trust me!’ And they go down a storm every time. He sometimes gives me a little wink on camera as if to say: ‘Told ya so.’”

“It all works itself out in rehearsals,” agrees Brendan, 61. “No matter what I’ve written, most of the really fun bits come to me as we rehearse or – as you can probably tell – when I’m actually doing the show.”

It’s at his home in Florida – where he lives with his wife, actress Jennifer Gibney (who plays Cathy Brown) – that Brendan writes the Christmas and New Year specials, and his contract with the BBC means he will continue to do so until at least 2020.

But while he loves the climate of the sunshine state – and his daily rounds of golf – the father of four never fails to return to Ireland to celebrate the festive season.

“Just before Christmas, we all meet up for a big family get-together and Dad does all the cooking.

“We’ll open presents – I don’t buy Dad anything now because anything he doesn’t have he doesn’t want; the happiest I have ever seen him is when I bought him a Zippo lighter! – and Dad will drink tea all night as he doesn’t drink [alcohol].

“Then, because I’ll be the tipsiest, he’ll tell me how stupid I am.

“We’re not The Waltons, but there’s never any rowing. Then he’ll invite all the staff from Mrs Brown’s Boys for a big Christmas party at his house too.”

“On Christmas Day, we all have dinner in our own homes, but at teatime everybody will gather in our house,” shares Brendan. “Jenny does a big tea and we have a huge pyjama party where we’ll sit down to watch the special.”

TV Magazine interview: Brendan O’Carroll and his son Danny vie for top slot in the festive ratings

“The rest of them will,” sighs Danny. “I’ll be straight on the phone after the special. My kids are getting too old now, so they want to stay at home and play with their toys instead.”

“I love Christmas,” beams Brendan.

“All my Christmases have been magic. Throughout my life, no matter how bad a year I’ve had, Christmas has always worked out… Well, nearly always: I remember when my daughter Fiona [Maria in Mrs Brown’s Boys] was five years old and wanted a bike.

“But I was skint that year so I got her a scooter and spent all day trying to convince her it was a bike!”

Brendan has never forgotten those days before the fame and fortune that Mrs Brown has delivered, and they’ve even prompted him to become a Santa Claus-type figure himself.

The character of Agnes Brown has changed Brendan’s life “beyond anything I ever imagined”, and he uses his new-found wealth remarkably generously.

Last year, for example, he paid for 2,500 Christmas dinners for less well-off families in Dublin and he has donated hundreds of thousands of pounds to charities since turning his fortunes around after being declared bankrupt in 1999.

“Without bulls***ting you, every day is about doing your bit to help those less well off, but particularly at Christmas,” says Brendan.

“It’s so sad to think of so many homeless or hungry people, and anyone lying awake at night worrying about what tomorrow will bring, at a time of year that’s so magical and happy for lots of others.”

It’s no secret that Mrs Brown’s Boys divides audiences but, as Danny reveals, on top of his father’s generosity, the series can have a rather heart-warming impact…

“I have had so many letters from families saying the show has changed their lives,” he says.

“There have been autistic kids that have never laughed before until watching Mrs Brown. That’s what is important.

“F*** the critics and f*** the people that bash the show on social media. I really couldn’t care less when people say they don’t like it. We are making people happy.”

And those fans will be overjoyed by some exclusive news Brendan and Danny have revealed to TV Magazine – there could be another movie on the way, and the Browns should soon have their own BBC1 chat show.

“The setting up and planning for a film takes a long time – you have to commit to it a good year beforehand – so the problem is we have the Mrs Brown’s Boys stage show touring the UK, Australia, New Zealand, Canada and South Africa, and it’s difficult to juggle both,” says Brendan.

“But I wouldn’t rule anything out.”

“We all loved how the first movie turned out and we think [film distributor] Universal want one as well, so it’s up to Dad,” adds Danny.

“I didn’t enjoy it as much as the TV series because you are not all together and we love filming live, but I wouldn’t say no to another movie.”

“And the rumours that Mrs Brown will have a chat show next year are nearly true,” grins Brendan.

“There is a light entertainment show in the offing, set in Mrs Brown’s house, and yes, part of it is a talk show – but it’s Cathy Brown who’s the host. Agnes will just sit in on it in case Cathy needs any ‘help’.”

Want to plan your Christmas viewing? Get your guide to What’s On TV from The Sun Online